Fix lock tests #37 & #42 by properly calling our XML error response delegator.
Fix lock tests #37 & #42 by properly calling our XML error response delegator.

* subversion/libsvn_ra_serf/util.c
  (handle_response): Appropriately set up the error callbacks or use our
  defaults if there is no XML error response with a friendly message.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1349545 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion